On-line TOC Analysis in the Drinking Water Treatment Process0 pages

On-line TOC Analysis in
the Drinking Water
Treatment Process

Introduction
In 1974 the Congress of the United States passed Public Law 93-523; the Safe Drinking Water Act (SDWA) to
protect public health by regulating the nation’s drinking water supply and protecting sources of drinking water. The
SDWA first went into effect on June 24, 1977 and has been amended multiple times.
The SDWA empowers the U.S. EPA to establish enforceable standards for contaminants in drinking water, along
with monitoring requirements and analytical test methods. The U.S. EPA has set standards for 90 chemical,
microbiological, radiological, and physical contaminants.
Total Organic Carbon (TOC) analysis measures organic contamination levels and is an important indicator of water
quality throughout the drinking water treatment process.

Drinking Water Treatment
The SDWA defines two types of drinking water systems. A Public Water system (PWS) serves at least 25 persons
or 15 service connections for at least 60 days per year. There are approximately 161,000 public water systems in
the United States. A Community Water System (CWS) is a public water system that supplies drinking water to
homes year-round. The majority of people in the U.S. (268 million) obtain their drinking water from one of the
54,000 community water systems.
Community water systems serving large populations generally rely upon surface water sources such as rivers,
lakes, and reservoirs. The quality of water from these sources determines the treatment process employed. The
basic steps of the drinking water treatment process are depicted in Figure 1 and described below.

1